The invention relates to a perovskite solar battery and a preparing method thereof. The perovskite solar battery comprises a transparent electrode, a hole transmission layer, a perovskite light absorption layer, an electronic transmission layer and a metal electrode. The hole transmission layer comprises at least one of PEDOT: PSS, P3HT, PTAA, PThTPTI, metallic oxide and graphene oxide. The electronic transmission layer comprises at least one of 58 pi-electronic fullerene PCBM, 56 pi-electronic fullerene OQMF, 54 pi-electronic fullerene OQBMF, PFN, PEIE, ZnO, TiO2, doped or modified ZnO or TiO2. The perovskite solar battery is high in energy exchange efficiency and low in cost and can be produced on a large scale, and the preparing method is simple in technology.